Use month data type for joined key.

members-base.scm

@@ -53,7 +53,8 @@
 	 member-file
 	 primes
 	 member-record
-	 ansi)
+	 ansi
+	 period)
 
  ;; Gets all files and symbolic links from given directory. The
  ;; symbolic links are represented by cons cells with car being the
@@ -273,8 +274,17 @@
 	  (di4 (dict-set di3 'students
 			 (filter-members-by-predicate mb member-student?)))
 	  (di5 (dict-set di4 'destroyed
-			 (filter-members-by-predicate mb member-destroyed?))))
-     di5))
+			 (filter-members-by-predicate mb member-destroyed?)))
+	  (di6 (dict-set di5 'month (*current-month*))))
+     di6))
+
+ ;; Returns a list two lists: keys, data.
+ ;; Each data record contains values for all keys.
+ (define (members-base-stats . args)
+   (let ((keys '(month total active suspended students destroyed invalid)))
+     (let mloop ((data '())
+		 (month '(2015 1))) ; TODO: *oldest-month*
+       #f)))
 
  ;; Basic information about members-base in human-readable form.
  (define (print-members-base-info mb)